Underground railway-conduit



(No Model.)

/ O. 0. GILMAN.

UNDERGROUND RAILWAY GONDUIT.

No. 446,861. Patented Feb. 24,1891.

nae/752 574 UNITED STATES PATENT OFFICE.

CHARLES CARROLL GILMAN, OF ELDORA, IOYVA.

UNDERGROUND RAlLWAY-CONDUIT.

SPECIFICATION forming part of Letters Patent No. 446,861, dated February 24., 1891.

I Application filed June 18, 1890. Serial No. 855,843. (No model.)

To all whom it may concern.-

Be it known that 1, CHARLES CARROLL GIL- MAN, a citizen of the United States, and a resident of Eldora, Iowa, have invented a new and useful Improvement in Underground Railway-Conduits, of which the following is a specification.

My invention relates to the construction of und erground-conduits for the accommodation of wire cables used for the propulsion of cable street-railway cars.

In the accompanying drawings forming part of this specification, Figure 1 represents a perspective view of an underground cableconduit embodying my invention, and Fig. 2 is a perspective View of-a porous earthenware section, as hereinafter described.

Conduits for cable railways are generally built from three to five feet below the surface of the ground and of varying shapes, but usually cylindrical, to allow not only the free movement longitudinally of the cable therein, but the safe passage of workmen employed around and about it in oiling sheaves &c., and for the drainage of water which may pour in from the street above. It will be evident, therefore, that the properties required of the materials used in the construction of such a conduit are freedom from decay, solidity, and proof against water. Consequently the best of hydraulic cements are made to do service in this construction, the same being molded into form in large sections or blocks and cemented continuously together in the ditch in the earth. At intervals of twentyfive feet or so metal sheaves 1, grooved for the support of the wire cable 4, are suspended from the side of iron struts 2, secured to the iron yokes 3, which latter are of the form and size of a transverse section of the conduit. The yokes serve to tie the sections together to maintain their general form and prevent swerving in or out by the shifting pressure of the earth packed outside about them, and thus very properly are termed yokes. A second and smaller yoke 5 is usually suspended. within the larger, (see drawings, Fig. 1,) which serves to tie the tracks together and affords the aperture or slot for the grip to pass down or through to seize the cable. My invention has nothing to do with these devices, but only with the substitution for the cement conduit of a conduit of like form and size, whatever that form and size may he,constructed of a different and cheaper material, but every way as permanent, enduring, and water-resistant, and embodying a great improvement on other conduits of this character because of its peculiar ability to take up and absorb sound, thus silencing the din caused by the rapid transit of the suspended cable or the revolving sheaves, and doing away with the roaring of passing trains caused by the reverberations from the resonant walls of the hidden conduit. This material is illustrated in Fig. 2 of the drawings, which shows a longitudinal section of porous earthenware four feet in length, three feet seven inches high, and four feet three inches extreme width, made in three longitudinal sections 6,

7, and 8, and united in one when placed in position, the shape as a whole being measurably the shape of the iron yokes which intersect it at intervals of twenty feet or more, 9 representing holes of arbitrary size which run lengthwise through the walls of each section, being made by the manufacturers to enable the effective drying of the green compositions before firing. The iron yokes are likewiseprovidedwith similarholes tolightentheir weight. These compositions are manufactured under the formulas prescribed in the specification of United States Patent No. 353,631, issued to me November 30, 188.6, for porous earthenware, and of course are extremely porous after coming from the firing-kilns, requiring subsequent special treatment to render them water-proofa prime necessity for the application herein described and set forth. This treatment may be of the simplest character and requires no lengthy description, the material being merely dipped into boiling asphaltum or its equivalent for a sufficient length of time to enable it to penetrate below the surface to the depth of an eighth or even a sixteenth of an inch, or, if preferred, may be coated with mortar or hydraulic cement troweled on or applied otherwise. If the latter material be used as the stucco, a workmanlike job requires thethorough wetting of the porous slabs with water before making the application, the long subsequent dampness of the ware enabling the cement coatings to set into a stone-like density, never to be detached save by disruption of the cov cred material itself. These scctionsare titted between the iron yokcs, as shown in the d 'awings, taking the place of the cement fillin; heretofore used.

I by no means limitmyselt to the particular size or form of the conduit described, as the material used may be applicable to any, and if not of unusual size may be turned out by a machine in one piece or more, or in the shape of blocks may be laid up as masonry. The man-holes, drains, and catch-basins usually accompanying this class of construction may also profitably be made of the same material thus treated.

Having thus described my invention, what I claim, and desire to secure by United States Letters Patent, is- 

